Eventually he settled in Rome, where, at an advanced age, he wrote (in Latin) a history of the Roman empire from the accession of Nerva to the death of Valens (96-378 C.E.), thus forming a continuation of the work of Tacitus. This history (Rerum Gestarum Libri XXXI) was originally in thirty-one books; of these the first thirteen are lost, the eighteen which remain cover the period from 353 to 378. As a whole it is extremely valuable, being a clear, comprehensive and impartial account of events by a contemporary of soldierly honesty, independent judgment and wide reading. "Ammianus is an accurate and faithful guide, who composed the history of his own times without indulging the prejudices and passions which usually affect the mind of a contemporary" (Gibbon). Although Ammianus was no doubt a pagan, his attitude towards Christianity is that of a man of the world, free from prejudices in favour of any form of belief. If anything he himself inclined to neo-Platonism. His style is generally harsh, often pompous and extremely obscure, occasionally even journalistic in tone, but the author's foreign origin and his military life and training partially explain this. Further, the work being intended for public recitation, some rhetorical embellishment was necessary, even at the cost of simplicity. It is a striking fact that Ammianus, though a professional soldier, gives excellent pictures of social and economic problems, and in his attitude to the non-Roman peoples of the empire he is far more broad-minded than writers like Livy and Tacitus; his digressions on the various countries he had visited are peculiarly interesting. In his description of the empire--the exhaustion produced by excessive taxation, the financial ruin of the middle classes, the progressive decline in the morale of the army--we find the explanation of its fall before the Goths twenty years after his death.